to take place. >>> rocks to act as shrapnel. we are not talking about iraq or afghanistan. that's how investigates are describing a soda bomb found at a marin city bus stop. jade hernandez joins us now to tell us this is not the first case in the area. >> reporter: no, pam, you're right and it seems innocent enough but someone is filling soda bottles like these with a concoction which explodes when anyone picks them up. one of these bottle bombs was found right here at the marin city bus stop yesterday afternoon. we just watched a sheriff's deputy pull up to this bus stop, get out of the car and then speed off. it appears he didn't want to comment on camera but fellow deputies found a bottle bomb just before 2:00 yesterday afternoon and no one was hurt but what could have happened is what worries county authorities. inside a bottle, rocks apparently placed inside to act as shrapnel, the mixture of fluid resulted in a gaseous buildup and then an explosion. back in may novato police warned residents about these types of devices. the school district even sent out an e-mail warning to